Author Topic: M33 - 17 Hours with DSLR  (Read 1827 times)

Offline AstroScience

  • PixInsight Addict
  • ***
  • Posts: 169
    • View Profile
M33 - 17 Hours with DSLR
« on: 2016 September 11 23:34:33 »
Hi guys,
in 2014 I had attempted to image this galaxy over two nights, but weather didn't played well so brought just 6 hours of data.
Last new moon I had an opportunity to shoot it again with same setup only this time I managed to pull additional 11 hours.
Here is the result of all combined data that I want to share with you : http://www.myastroscience.com/m33-17hours-dslr
Thank you!


« Last Edit: 2016 September 14 11:07:55 by AstroScience »

Offline wimvb

  • PixInsight Enthusiast
  • **
  • Posts: 85
    • View Profile
    • Wims place
Re: M33 - 17 Hours with DSLR
« Reply #1 on: 2016 September 14 10:15:43 »
That's a great image. I love the detail you got out of this target.
My understanding is that single sub exposure determines brightness and the level of faint detail you can get, while number of subs determines noise. But of course, less noise means that it's easier to get to that faint detail.

Thanks for sharing
Wim

AZ EQ6 GT + EQ3 PRO, SW 150P, ZWO ASI174MM-Cool, Pentax K20D (retired),
SW ST80 + ZWO ASI120MM + Lin_guider

Offline AstroScience

  • PixInsight Addict
  • ***
  • Posts: 169
    • View Profile
Re: M33 - 17 Hours with DSLR
« Reply #2 on: 2016 September 14 10:52:29 »
Thank you, Wim, glad you liked it.
about single exposure, not exactly. You may shot a single sub and see no faint details at all, but they are still recorded, it's just they are buried in the noise floor.
As you continue to make more single exposures and stack them, the noise is going to be reduced while faint signal going to be stronger. As more total exposure time you do, your faint details slowly start to raise above the noise floor.

Your single exposure though, should be aimed to be sky limited, when your sky background swamps the readnoise of your camera. It's the TOTAL exposure time will determine how deep you'll go and how much of a faint details you'll be able to pull out.

Offline wimvb

  • PixInsight Enthusiast
  • **
  • Posts: 85
    • View Profile
    • Wims place
Re: M33 - 17 Hours with DSLR
« Reply #3 on: 2016 September 19 09:01:36 »
I agree to that, but I phrased it poorly. Faint detail is raised above the noise floor, because the noise floor is lowered by stacking, not because the signal level is raised by stacking.
Wim

AZ EQ6 GT + EQ3 PRO, SW 150P, ZWO ASI174MM-Cool, Pentax K20D (retired),
SW ST80 + ZWO ASI120MM + Lin_guider

Offline AstroScience

  • PixInsight Addict
  • ***
  • Posts: 169
    • View Profile
Re: M33 - 17 Hours with DSLR
« Reply #4 on: 2016 September 19 09:10:03 »
Sure, signal doesn't get stronger per se, but against noise.

Offline RickS

  • PTeam Member
  • PixInsight Jedi
  • *****
  • Posts: 1295
    • View Profile
Re: M33 - 17 Hours with DSLR
« Reply #5 on: 2016 September 20 01:33:30 »
That's a great M33, Sergio.  Well done!

Offline AstroScience

  • PixInsight Addict
  • ***
  • Posts: 169
    • View Profile
Re: M33 - 17 Hours with DSLR
« Reply #6 on: 2016 September 20 12:12:02 »
Thank you, Rick!